Silvia Club of NSW

Hey Guys,

My mate recently got himself a 180sx and what we noticed was when you just rev the car without any load the boost guage reads 10psi at around 6rpm, we thought that the guage maybe playing up, we swapped with a known one and still the same thing. My car only goes to 0 when revved, is my car playing up or is his? If so why does his car make that much boost without any load?

Thanks

a few things can affect boost...

does your mate have a air filter, intercooler, blow off valve and other mods?

also there is some boost produced even if a car is stock so i guess mabye your car is playing up if it shows 0 flat on the boost guage?

correct me if im wrong - im always wrong

hehe

-mark

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depending on the turbo and the wastegate and boost controller types, its possible to get some boost with free revving

10psi at 6k?? why u revving that hard with no load on the engine?

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M35 Stagea.info @ http://www.m35stagea.info/

another thing that can contribute to boost while under no load and that is..
severe retard in the timing and/or running too rich. a combination of both will certainly give boost under no load.

just like how a launch controller works on a haltech set up.
i can spool mine up to 18psi standing still.

I just got a boost gauge in my stock sr20det silvia and wen I rev it, it never shows any boost even though the bov vents. It shouldnt go passed 0 on the gauge while revving with no load.
So me thinks maybe its the location of where the vacuum line for the gauge is tee'd in.

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When I grow up I wanna win the lotto...

got anti-lag?

my one revs and still gets boost, just that its get rev hard to get it just normal reving will only get 4 to 5 psi

Hey,
Had a quick look at his engine,
he has only got the standard blow off valve, stock intercooler and ashitty pod filter, no aftermarket ecu and definately no anti-lag. The t peice has been put in the correct place.
Maybe the timing is retarded, haven't checked that, don't really see why it would be running that rich to spool the turbo up that easily.
Still stunned.

thanks

i get boost too when the cars just in nuetral...cuz i got a BOV i try and rev it abit until i get sum boost and then let go of the throtle and cshhchhshcshhh it goes..lol..its only abit but still...hehehehe

I'd definitely be checking the timing.

Could even be the cam timing if it's been apart and put back together wrong.
There's a pretty big risk of cooking the turbo too.

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The Engine Whisperer - fixer of things

doesnt mean ur on boost

it just means that the vacuum level on the BOV was enough that it opens up. i can make my BOV 'go off' way before its on boost

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M35 Stagea.info @ http://www.m35stagea.info/

all the cars I have ever owned or driven that are forced have showen boost readings while free-revving....I thought it was normal, I was under the impression that an engine that is free revving is exactly the same as an engine that has a load place against it, the only difference is the restriction of having a load on the engine, and it would never change how the engine operated.

The only real difference that I have noticed is the ECU will limit boost dependant on the intake of air as recorded by the AFM. If your not drawing enough air to make the boost you are trying to make the ECU will back the boost off to a level it can handle.

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Do Unto Others, Before They Do Unto You
- Hobzta

with more load on the engine you are going to produce boost. as for free revving, the cars i have seen dont. then again they were stock ECUs, aftermarket ones - PFC etc - may allow this. most stock nissan ECUs limit boost in low gears, neutral and reverse get very little - if none at all!

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M35 Stagea.info @ http://www.m35stagea.info/